The short answer
On a Bosch dryer, water where a dryer should not produce any usually comes down to a full or unseated condensate tank rather than anything deeper in the machine: a condenser dryer collects the water it removes from the load, and a tank that is full or not pushed home overflows as a matter of course. That keeps it an owner check first, not a service call. Start here: empty the condensate tank and clean the condenser, because on a ventless Bosch these two are the entire moisture path and both are owner-serviceable.
What you are seeing
- A damp patch on the floor under or behind the machine
- Water inside the drum after a cycle
- Water running from the lower access door
- Not this fault: Water from the washer standpipe next to it, which is a plumbing fault
- Not this fault: Damp clothes with a dry floor, which is a drying-performance problem
- Body: Bosch builds this dryer as a compact ventless condenser dryer that condenses moisture out of the drum air and collects it in a tank or pumps it to a drain, with a lint filter and a separate condenser unit behind a lower door. That architecture decides which of these you see first.
- Also check note: If these fit better, the fault is a different one.
Likely causes, in order
- A full or unseated condensate tank — Why this rank: A Bosch condenser dryer collects the water it takes out of the load in a tank, so a full or badly seated tank puts water on the floor as a matter of course.
- A clogged condenser block — Why this rank: The Bosch condenser behind the lower door clogs with lint, which floods the sump and overflows before it ever affects drying.
- The condensate pump or its hose — Why this rank: Where the Bosch is plumbed to a drain, the condensate pump and its hose are the leak path rather than any supply line.
- Water arriving from something other than the dryer — Why this rank: A vented dryer with no steam function has no water in it at all.
- Condensation in the duct running back into the machine — Why this rank: A long or cold duct run condenses the moisture the dryer has just removed.
- Body: Ranked for a Bosch dryer specifically.
What to check, in order
- Body: The order follows the ranking, and the ranking follows the platform. First: pull the tank out fully, empty it and push it back until it clicks. It goes first because a Bosch condenser dryer collects the water it takes out of the load in a tank, so a full or badly seated tank puts water on the floor as a matter of course. Second: release the condenser behind the lower door and rinse it until water passes freely. With the first check clean, this is what the Bosch platform makes next most likely. Third: look at the small drain hose where it leaves the cabinet. Only after those three is it worth reaching for water arriving from something other than the dryer: it costs more to get at, and it does not explain the first three coming back clean.
Checks you can make
- Pull the condensate tank out fully, empty it and push it back until it seats with a click. A tank that is not home is the most common source of water on the floor under a Bosch. — Tools: none — Time: about five minutes
- Dry the floor completely under and behind the machine, then run the dryer alone with nothing else in the room using a drain, and look again. — Tools: towel — Time: about forty minutes
- Open the lower door, release the condenser unit and rinse it under a tap until water runs through the fins freely. Lint there floods the sump and overflows the cabinet. — Tools: none — Time: about twenty minutes
- Body: Stop at the first step that would need a meter on live terminals or a sealed assembly opened.
Before you open anything
Safety
Switch the machine off at its breaker or unplug it before opening anything, and shut the water supply if the fault involves water. Unplug the appliance or switch off its breaker before removing any panel. A capacitor can hold a charge after the power is off. These machines are heavy and move when they are worked on. Get help before tilting or walking one out, and never put a hand under a raised cabinet.
When to call
The line is not difficulty, it is what the next step costs and risks. Call when: the machine is a condenser or heat-pump model and the leak returns after the tank and condenser have been cleared water is reaching the electrical connections or the terminal block at the rear
What this page omits
This is generalized information: it ranks causes for the Bosch dryer range as one platform, not for a single model. Where a page exists for your specific model it is the more specific one and takes precedence over this. The narrower pages below cover the other presentations of this symptom.
Entries: - [Bosch Dryer: Controls, Display or Error Code](/blog/bosch-dryer-control-fault) - [Bosch Dryer: Does Not Clean or Dry](/blog/bosch-dryer-cleaning-performance)
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Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
